Grinding mill liner

ABSTRACT

A liner element for lining a vertical grinding mill agitator including one or more primary mounting portions configured to releasably mount the liner to a shaft of the agitator; and one or more secondary mounting portions configured to releasably mount one or more wear members to the liner. A liner segment including the liner element and at least one wear member is also disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 16/957,041, filed Jun. 22, 2020, which is a national stageapplication under 35 USC 371 of International Application No.PCT/AU2018/051400, filed Dec. 21, 2018, which claims the priority ofAustralian Application No. 2017905155 filed Dec. 22, 2017, the entirecontents of each priority application of which are incorporated hereinby reference.

FIELD OF THE DISCLOSURE

This disclosure relates to liners for grinding mills of the type thatinclude a generally vertically oriented agitator. Such mills are knownas, for example, vertical grinding mills, tower mills, vertical regrindmills or stirred mills.

BACKGROUND OF THE DISCLOSURE

Vertical grinding mills (or tower mills, stirred mills, vertical regrindmills, etc.) generally include a chamber containing the material to beground, grinding media (e.g. steel or ceramic balls) and water. Suchmills further include an agitator disposed in the chamber, which rotatesabout a generally vertical longitudinal axis to move the contents of thechamber. This movement of the contents of the chamber (e.g. between thegrinding media and material to be ground) results in abrasion and/orattrition of the material to be ground.

In general, the agitator of the vertical grinding mills comprises alongitudinal shaft that supports one or more blades that extend radiallyfrom the shaft. The blades may be helically formed about the shaft ormay be planar (i.e. so as to form discs extending about the shaft). Itis predominantly the movement of these blades that results in movementof the contents of the chamber.

The exposed nature of these blades (e.g. to the abrasive contents of thechamber) means that they can be particularly susceptible to wear inoperation. When such wear occurs, replacement of the blades can beproblematic due to their considerable size and weight.

It is to be understood that, if any prior art is referred to herein,such reference does not constitute an admission that the prior art formsa part of the common general knowledge in the art, in Australia or anyother country.

SUMMARY OF THE DISCLOSURE

Disclosed herein is a liner element for lining a vertical grinding millagitator. The liner element comprises one or more primary mountingportions configured to releasably mount the liner to a shaft of theagitator, and one or more secondary mounting portions configured toreleasably mount one or more wear members to the liner.

As will be discussed further below, the provision of primary andsecondary releasable mounting portions provides versatility in regardsto use of the liner element. The primary mounting portions allowreplacement of the liner element on the shaft (or a blade of the shaft)of the agitator. The secondary mounting portions allow replacement ofwear members on the liner element without the need to remove the linerelement from its mounting on the shaft.

In one embodiment each secondary mounting portion may be configured tomount the one or more wear members at a peripheral edge of the linerelement. The peripheral edge of the liner element may be particularlysusceptible to wear in use. Thus, the wear members may be mounted at aportion of the liner element that experiences more wear than otherportions of the liner element. The provision of wear members at theselocations means that instead of the liner element needing replacement,the wear members can be replaced (which may be both less time consumingand less expensive).

The secondary mounting portions may be configured to mount the one ormore wear members at positions other than the peripheral edge of theliner element. The secondary mounting portions may be configured tomount one or more wear members at one or more locations of the linerelement that are particularly susceptible to wear (e.g. that experiencegreater wear than the average or normal wear of the liner element) inuse. Such areas may be e.g. be protruding portions of the liner element(i.e. protruding from planar surfaces of the liner element).

In one embodiment each primary mounting portion may comprise an aperturefor receipt of a fastener, to releasably mount the liner element to theshaft of the agitator. The fastener may be in the form of a bolt. Theaperture may align with a corresponding in e.g. a blade of the shaft andthe fastener may be received through the apertures. The aperture mayhave an elongate shape. The long axis of the elongate aperture may begenerally aligned in a circumferential direction relative to an axis ofthe shaft. The elongate shape of the aperture may allow some leeway inmounting the line element to the shaft.

In one embodiment the liner element may be configured to be mounted to ahelical blade of the agitator shaft. The liner element may have agenerally helical form. The liner element may be in the form of ahelical segment (i.e. the shape may be such that it is a segment of alarger helical shape).

In one embodiment the liner element may be configured to be mounted to adisc shaped blade of the agitator shaft. The liner element may comprisea generally planar form. The liner element may be generally in the formof a sector of a circle.

In one embodiment the liner element may comprise a proximate edge thatlocates proximate the shaft when the liner element is mounted thereto.The liner element may further comprise a distal edge that is distal fromthe shaft when the liner element is mounted thereto. The proximate edgeof the liner element may abut the shaft when mounted thereto. Theproximate edge may comprise indentations. The distal edge may be curved.

In one embodiment the one or more secondary mounting portions may bespaced along the distal edge of the liner element. In this way, the oneor more wear members may be mounted at the distal edge. This positioningof the secondary mounting portions may facilitate mounting of the wearmembers due to the accessibility of the distal edge (i.e. as opposed toother portions of the liner element when mounted to the shaft).

In one embodiment the distal edge may comprise an enlarged portion thatmay define a lip extending along the distal edge. The enlarged portionmay increase the strength of the liner element at the portion where thewear members are to be mounted (e.g. when the secondary mountingportions are also at the distal edge). The liner element may beconfigured to be mounted to a blade of the agitator shaft, and the lipmay extend over an edge of the blade when mounted thereto. In this way,the liner element may provide protection to the edge (or an edgesurface) of the blade. Further, the lip may provide a stop, such thatwhen mounting the liner element onto the blade, abutment of the lipagainst the edge of the blade ensures correct alignment of the linerelement on the blade (e.g. in the radial direction).

In one embodiment the liner element may further comprise an attachmentmeans for attachment of a lifting apparatus for lifting the linerelement. The attachment means may comprise a lug. This may facilitatehandling of the liner element (e.g. for installation and replacement).

Further disclosed is a liner segment comprising a liner element as setforth above, and one or more wear members. Each wear member comprises awear member mounting portion for releasably mounting the wear member toa corresponding secondary mounting portion of the liner element. Theliner may comprise a plurality of wear members.

As set forth above, the provision of replaceable wear members canprovide versatility in regards to maintaining the agitator. The abilityto replace the wear members provides an operator with the opportunity toonly replace those portions (e.g. particular wear members) of theagitator that are worn and require replacement.

In one embodiment each secondary mounting portion comprises aprotrusion, and each wear member comprises a socket for receipt of theprotrusion of a respective wear member. Alternatively, in one embodimenteach wear member mounting portion may comprise a protrusion, and eachsecondary mounting portion may comprise a socket for receipt of theprotrusion of a respective wear member.

This may enable the replaceable mounting of the wear member (or members)to the liner element. The shape of the protrusion may be generallycomplementary to the shape of the socket. The mounting may be in theform of a transition (e.g. tight) fit between the socket and theprotrusion. A retainer arrangement for retaining the protrusion in thesocket may be provided. The retainer arrangement may restrict movementof the protrusion out of the socket.

The replaceable mounting may alternatively or additionally be in theform of a fastener and a threaded (or non-threaded) aperture. Forexample, the wear member mounting portion (of the wear member) maycomprise an aperture and the secondary mounting portion (of the linerelement) may comprise a further aperture. The apertures may be alignedand a bolt can be passed through the apertures to mount the wear memberto the liner element. The bolt may comprise a locking arrangement toretain the bolt in the apertures. The aperture of the secondary mountingarrangement may comprise a thread to retain the bolt.

Other arrangements may provide mounting of the one or more wear membersto the liner element, as long as such arrangements provide releasablemounting such that the wear members can be released from the linerelement (e.g. without damage to the liner element and without removingthe ability to replace the removed wear member). For example, mountingarrangements using threads, moveable (e.g. spring loaded) detents,clips, deformable portions, etc. may be suitable for releasable mountingof the one or more wear members to the liner element.

In one embodiment the liner segment may comprise a mounting member thatmay be configured to be mounted or secured to one or more secondarymounting portions and one or more wear members mounting portions. Inthis way, the wear members may not be directly mounted to the linerelement and may instead be mounted to the liner element via the mountingmember. The mounting member may additionally provide support to theliner element and or wear member(s). The mounting member may be in theform of a frame or plate (e.g. base plate) that interconnected the wearmember(s) and the liner element. In one embodiment, the mounting membermay be a base plate that is also secured to the shaft.

In one embodiment each protrusion may comprise a first recess and eachsocket comprises a second recess, the recesses being arranged such thatwhen a protrusion of the one or more protrusions is received in arespective socket, the recesses of the protrusion and socket align todefine a lock passage (i.e. retainer arrangement). The alignment may bein the form of longitudinal axes of the recesses being aligned. Theliner segment may comprise one or more locks. Each lock may be forreceipt in a lock passage to lock a respective protrusion in arespective socket. Each recesses may be in the form of a passage thatextends from one surface to another, or may be a blind hole that onlyextends partway into the material.

Thus, the lock may be positioned so as to span the joint between thewear member and liner element such that the lock restricts movement ofthe wear member relative to the liner element.

In one embodiment each lock may comprise a retainer for releasablyretaining the lock in a position in which the lock locks the protrusionin the socket. The retainer may be in the form of a detent or groovethat interact to retain the lock in the locking position. The retainermay alternatively be a spring-loaded member or a compressible member.

In one embodiment the liner elements and the one or more wear membersare made from the same or similar material.

In one embodiment the liner element may be formed of a differentmaterial to the one or more wear members. The one or more wear membersmay be formed of a harder material than the liner element.

The liner element and/or the wear members may be formed of cast whiteiron or steel that may be cast or plate or fabricated. The liner elementand/or wear members may additionally comprise ceramic tiles that lineits surface. The liner and/or wear members may alternatively comprisehard facing (e.g. in the form of a weld overlay).

The liner element and/or wear members may alternatively be formed of arubber composite. This may be in the form of a rubber liner frame orbaseplate (which may be cast, plate or fabricated). The liner elementand/or wear members, when formed of a rubber composite, may include aceramic tile inlay on a surface thereof.

In one embodiment each wear member may be configured such that, whenmounted to the liner element, an in use upper surface of the wear membermay form a generally continuous surface with an in use upper surface ofthe liner element. The upper surface of the wear member may be flushwith the upper surface of the liner element. This may avoid exposededges that may be susceptible to wear in use.

In one embodiment, when mounted to the liner element, the one or morewear members may be arranged so as to experience more wear than theliner element in use. The wear members may be mounted to the linerelement at locations that are more susceptible to wear in use.

In one embodiment the liner segment comprises a plurality of wearmembers.

In one embodiment, when mounted, the plurality of wear members may forman extension of the edge of the liner element having a generallycontinuous profile. This may avoid exposed edges that may be susceptibleto wear in use.

In one embodiment, when mounted to the liner element, the plurality ofwear members may be adjacent to one another. This may avoid gaps betweenthe wear members where the liner element may be susceptible to wear.

In one embodiment, when mounted to the liner element, the plurality ofwear members may not be directly mounted to the shaft. This may ensurethat the liner segment can be removed as a single piece.

Also disclosed is a liner segment for a vertical grinding mill agitator.The liner segment comprises a body formed of a first material and aperipheral portion formed of a second material that is different to thefirst material. The liner segment further comprises a mounting portionfor releasably mounting the liner to a shaft of the agitator. Thematerial of the peripheral portion may be harder than the material ofthe body.

The body and/or the peripheral portion may be formed of cast white ironor steel that may be cast or plate or fabricated. The body and/or theperipheral portion may additionally comprise ceramic tiles that line itssurface. The body and/or the peripheral portion may alternativelycomprise hard facing (e.g. in the form of a weld overlay).

The body and/or the peripheral portion may alternatively be formed of arubber composite. This may be in the form of a rubber liner frame orbaseplate (which may be cast, plate or fabricated). The body and/or theperipheral portion, when formed of a rubber composite, may include aceramic tile inlay on a surface thereof.

Further disclosed is a wear member for a liner segment as set forthabove in at least one embodiment, the wear member comprising a body anda wear member mounting portion for releasably mounting the wear memberto a corresponding secondary mounting portion of the liner element.

The wear member may be otherwise as disclosed in respect of any form ofthe liner segment as set forth above.

Further disclosed is an agitator comprising a shaft having a supportstructure and a plurality of liner segments as set forth above in atleast one embodiment, mounted to the support structure.

Further disclosed is a method of maintaining an agitator for a verticalgrinding mill. The method comprises mounting a replaceable liner to theagitator, mounting a wear element to the replaceable liner; andreplacing the wear element mounted to the replaceable liner with areplacement wear element, while the wear liner remains mounted to theagitator.

BRIEF DESCRIPTION OF THE FIGURES

Embodiments will now be described by way of example only, with referenceto the accompanying drawings in which:

FIG. 1A is a perspective view of an agitator for a vertical grindingmill including a plurality of liner segments;

FIG. 1B is a perspective view of the shaft of the agitator of FIG. 1A;

FIG. 1C is a perspective view of a first liner segment of the agitatorof FIG. 1A;

FIG. 1D is a perspective view of a wear member of the first linersegment of FIG. 1C;

FIG. 1E is a detailed view of a secondary mounting portion of the firstliner segment of FIG. 1C;

FIG. 1F is a perspective view of the top of a second liner segment ofthe agitator of FIG. 1A, with wear members mounted thereto;

FIG. 1G is a perspective view of the underside of the second linersegment of FIG. 1F;

FIG. 1H is a perspective view of a wear member of the second linersegment of FIGS. 1F and 1G without the second liner element mountedthereto;

FIGS. 1I and 1J are side views of a lock;

FIG. 2 is a section view of a further embodiment of a liner segment;

FIG. 3A is a perspective view of a further embodiment of a first linersegment;

FIG. 3B is a perspective view of the first liner element of the firstliner segment of FIG. 3A;

FIG. 3C is a perspective view of one of the wear members of the firstliner segment of FIG. 3A;

FIG. 3D is a sectional view of the liner segment of FIG. 3A mounted toan agitator blade;

FIG. 4A is a top perspective view of a further embodiment of a secondliner segment with wear members mounted thereto;

FIG. 4B is a perspective view of the second liner element of the secondliner segment of FIG. 4A; and

FIG. 4C is a perspective view of one of the wear members of the secondliner segment of FIG. 4A.

DETAILED DESCRIPTION OF THE DISCLOSURE

In the following detailed description, reference is made to accompanyingdrawings which form a part of the detailed description. The illustrativeembodiments described in the detailed description, depicted in thedrawings and defined in the claims, are not intended to be limiting.Other embodiments may be utilised and other changes may be made withoutdeparting from the spirit or scope of the subject matter presented. Itwill be readily understood that the aspects of the present disclosure,as generally described herein and illustrated in the drawings can bearranged, substituted, combined, separated and designed in a widevariety of different configurations, all of which are contemplated inthis disclosure.

FIGS. 1A and 1B show an agitator 100 for a vertical grinding mill. Theagitator 100 comprises an elongate circular shaft 102 that extends alonga generally vertical (in use) longitudinal axis. An in use upper end ofthe shaft 102 comprises a coupling portion 104 for coupling to a driverof a vertical grinding mill. Although not illustrated, the couplingportion 104 may be coupled to e.g. a drive shaft by way of a pluralityof fasteners, locking mechanism, welding, etc. Thus, in operation, theagitator 100 may be located in a chamber of a vertical grinding mill,and may be rotated (about the longitudinal axis) to grind material inthe chamber.

The shaft 102 of the illustrated agitator 100 further comprises twohelical blades 106 in a double helix configuration. Each blade 106comprises a single flight that is secured (e.g. by welding) at an inside(proximal) edge 108 to the cylindrical body of the shaft 102 and extendsradially from the proximal edge 108 to an outside (distal) edge 110. Aplurality of apertures 112 extend through each blade 106. The apertures112 are spaced along a line that generally follows the helical curve ofthe blade 106 (and the edges 108, 110). Each aperture 112 is closer tothe distal edge 110 of the blade 106 than the proximal edge 108.

As is apparent from FIG. 1A, the agitator 100 further comprises twoliners 114 that each line a respective helical blade 106. Each liner 114is helical and has a form that generally corresponds to the helical formof the respective blade 106 that it lines (or covers). The liners 114are each formed from a plurality of liner segments 116 that locateadjacent one another along the length of the liner 114.

Separating each liner 114 into these liner segments 116 may facilitateinstallation and replacement of the liner 114. For example, it may beeasier to handle individual liner segments 116 rather than an entireliner 114 during installation or replacement. Furthermore, in operation,the wear rate may not be consistent across the entire liner 114. Thus,one or more portions of each liner 114 may experience more wear thanother portions. In such circumstances it may be desirable to replacethat portion without replacing the entire liner 114. The provision ofliner segments 116 (as opposed to a single liner 114 for each blade 106)facilitates such replacement. This replacement is further facilitated byan attachment means located at an upper corner (proximate the shaft) ofthe liner segment 116, which in the present embodiment is in the form ofa lifting lug 118. The lifting lug 118 can be used to attach the linersegment 116 to e.g. a hoist, to remove the liner segment 116 from theagitator 100. Each liner segment 116 may alternatively or additionallyinclude a threaded insert (e.g. disposed in a central portion of theliner). The threaded insert may be mounted by way of adhesive, or may becast into the liner. When present, a threaded lifting eye may be used(with the threaded insert) to handle the liner segment 116.

FIG. 1C shows a liner segment 116 in more detail. As is apparent fromthis figure, the liner segment 116 is formed from a liner element 120and a plurality of (in this case three) wear members 122 mounted to theliner element 120. The liner element 120 has a generally helical formand comprises a curved inside (proximal) edge 124 that generallyfollows, and abuts, an outer surface of the body of the shaft 102 wheninstalled. The liner element 120 extends radially outward from theproximal edge to a similarly curved outside (distal) edge 126. The widthof the liner element 120 (i.e. between the proximal 124 and distal 126edges) is larger than the width of corresponding helical blade 106 onwhich the liner element is to be mounted. In this way, the liner element120 extends across the helical blade 120 and beyond the distal edge 110of the helical blade 106 when installed so as to cover (and protect) theupper surface of the helical blade 106.

The liner element 120 has a generally consistent thickness across itswidth, except for at the distal edge 126. The distal edge 126 comprisesa thicker portion that defines a lip 128 of the liner element 120. Wheninstalled, this lip 128 hangs over (or wraps around) the distal edge 110of the helical blade 106 so as to provide protection to the distal edge110 of the helical blade 106.

The liner element 120 can be secured in this position by way of aplurality of primary mounting portions, which in the present embodimentare in the form of mounting apertures 130 extending through the linerelement 120. The mounting apertures 130 are spaced along a line thatgenerally follows the curve of the proximal 124 and distal 126 edges.The positioning of the mounting apertures 130 corresponds to thepositioning of the apertures 112 formed in the helical blades 106 (towhich the liner element 120 is mounted). Hence, the liner element 120can be positioned on a helical blade 106 such that each set of apertures112, 130 (i.e. on the helical blade 106 and the liner element 120) arealigned. In this way, a bolt can be received through each alignedaperture pair 112, 130 to releasably mount the liner element 120 to theshaft 102 of the agitator 100, via the helical blade 106. To assist inthis process, the mounting apertures 130 of the liner element 120 areelongate (so as to have a generally obround shape). The long axis ofeach elongate aperture 130 is oriented in the direction along the curveof the helix (i.e. so as to be generally parallel to the proximal 124and distal 126 edges). This provides some flexibility in regard toalignment of the apertures 112, 130 (and means that exact alignment maynot be necessary), so as to facilitate mounting of the liner element 120to the shaft 102 of the agitator 100.

The liner element 120 further comprises a plurality (in this case three)secondary mounting portions, which in the present embodiment comprisesockets 132 formed in the distal edge 126 of the liner element 120. Aswill be described in more detail below, each socket 132 is configured toallow releasable mounting of a corresponding wear member 122 to theliner element 120.

Three such wear members 122 are mounted at the distal edge 126 of theliner element 120 illustrated in FIG. 1C. Each wear member 122 extendsalong the distal edge 126 of the liner element 126 and includes a body133 having a generally rectangular profile. The wear members 122collectively form a generally continuous edge profile. That is, thesurfaces of adjacent wear members 122 are flush with one another (wheninstalled) so as to form a generally continuous profile. The in useupper 134 and lower 136 surfaces of the wear member body 133 are alsoflush with the corresponding upper 138 and lower 140 surfaces (on thelip 128) of the liner element 120. In this way, the wear members 122, ineffect, form an extension of the edge of the liner element 120 distaledge 126. The smooth transition between the surfaces 138, 140 of theliner element 120 and the surfaces 134, 136 of the wear members 122avoids exposed edges that would otherwise be susceptible to wear in use.

An internal (or proximal) surface 142 of each wear member 122 abuts thedistal edge 126 of the liner element 120 when mounted thereto. Aprotrusion 144 extends from this internal surface 142 and iscomplementary in form to a corresponding socket 132 formed in the distaledge 126 of the liner element 120. In this way, the protrusion 144 canbe received in the corresponding socket 132 to mount the wear member 122to the liner element 120 (as show in FIG. 1C).

The protrusion 144 and socket 132 are more clearly shown in FIGS. 1D and1E. For clarity, only this socket/protrusion pair 132, 144 will bedescribed, but it should be appreciated that this pair 132, 144 isrepresentative of all socket/protrusion pairs 132, 144 forming part ofthe liner segment 116. As is apparent from FIG. 1D in particular, theprotrusion 144 has a generally rectangular profile. The edges of theprotrusion 144 are rounded, as is the connection between the protrusion144 and the internal surface 142 of the wear member 122. The entrance,and the internal edges of the socket 132 are similarly rounded. This canreduce stress concentrations, facilitate manufacture, and may assistinsertion of the protrusion 144 into the socket 132 (e.g. the roundedsurfaces may guide the protrusion 144 into the socket 132).

Raised mating surfaces 146 are provided on the protrusion 144 and in thesocket 132. The protrusion 144 comprises raised mating surface 146 onits opposite upper and lower surfaces, and on its end surface (at thedistal end of the protrusion). The socket 132 comprises two raisedsurfaces on each of its opposing upper and lower surfaces, and on itsinternal end surface. A raised mating surface 146 is also provided oneach of the side surfaces of the socket 132. These raised surfaces 146facilitate insertion of the protrusion 144 into the socket 132, andsubsequent removal of the protrusion 144 from the socket 132.

The socket 132 comprises an associated recess, in the form of a bore148, which extends from the upper surface 138 of the liner element 120(at the distal edge) through to the lower surface 140 of the linerelement 120 (i.e. so as to extend across the socket 132). The bore 148extends at an angle (i.e. on decline) relative to the upper surface 138of the liner element 120 (i.e. in the direction of the distal edge 126of the liner element 120). The protrusion 144 also comprises acorresponding recess in the form of a bore 150 that extends through theprotrusion 144 from the upper surface of the protrusion 144 to the lowersurface of the protrusion 144. The bore 150 formed in the protrusion 144has a generally circular cross-profile that tapers inwardly from an inuse upper end of the bore 150 (at the upper surface of the protrusion144) to an in use lower end of the bore 150 (at the lower surface of theprotrusion 144).

When the protrusion 144 is received in the socket 132, the bore 148 ofthe socket 132 and bore 150 of the protrusion 144 align along a commonlongitudinal axis (to form a lock passage). In this way, a lock 152 canbe received in the aligned bores 148, 150, through the opening of thesocket bore 148 at the upper surface of the liner element 120. Locationof the lock 152 in the aligned bores 148, 150 can retain the respectiveprotrusion 144 in the corresponding socket, 132 so as to mount thecorresponding wear member 122 to the liner element 120 (and so as toprevent dislodgement of the wear member 122 from the liner element 120).

Although not apparent from the present figures, the lock 152 can includea retainer arrangement for releasably retaining the lock 152 in aposition in which it locks the protrusion in the socket.

The lock 152 is better shown in FIGS. 1I and 1J. The retainerarrangement is in the form of a groove 174 having an axial portion 176(extending generally parallel to a longitudinal axis of the lock 152)and a helical portion 178 (extending circumferentially). The bore 150 ofeach protrusion 144 comprises a detent (not shown) extending inwardlyfrom the internal wall of the bore 150. As the lock 152 is inserted intothe bore 150, the groove 174 and detent interengage and the groove 174rides over the detent. Initially the detent travels along the axialportion 176 of the groove 174, which enables insertion of the lock 152into the bore 150. When the detent reaches the helical portion 178 ofthe groove 174, the lock 152 is caused to rotate (i.e. due to the detentfollowing the groove). At its distal end, the groove 174 comprises adeeper portion that defines a seat 180. As the detent travels along thegroove 174 it is compressed. Once the detent reaches the seat 180 of thegroove 174, after the lock 152 is turned through the helical portion178, it is able to decompress so as to extend into the seat 180 and soas to be retained in the seat 180.

To enable this movement of the lock 152 (i.e. into the bores 148, 150and then into the retained position), an end of the lock 152 maycomprise an engagement means. This engagement means may be in the formof a (e.g. hexagonal) socket for receipt of a tool to push the lock 152into the recesses and then rotate the lock 152 into the retainedposition.

As should be appreciated each lock 152 can be removed from the alignedbores 148, 150 by rotation in the opposite direction (e.g. using atool). When its respective lock 152 is removed, the protrusion 144 canbe moved out of its corresponding socket 132, and in this way the wearmember 122 is released from the liner element 120. This means that thewear members 122 can be replaced without requiring removal of theremaining wear members 122 from the liner element 120, or of the linerelement 120 from the helical blade 106. This may allow improvedmanagement of the wear of the agitator 100. For example, it avoids theneeds to replace an entire liner element 120, which can be both costlyand difficult (due to the size of such liner elements), when only oneportion of that liner element 120 is worn.

Wear of the liner elements 120 (and wear members 122) may also bemanaged by providing wear members 122 that are formed of a differentmaterial to the liner element 120. For example, the liner element 120and/or wear members 122 may be formed of white iron, steel or rubber,and may optionally include ceramic inserts or plating.

FIGS. 1F, 1H and 1G illustrate a further liner segment 116′. The furtherliner segment 116′ generally includes the same features as thepreviously described liner segment 116, but differs in that it isconfigured for mounting at the in use lower end of the shaft 102. Due tothis location, the shape of this further liner segment 116′, and thelocation of some of the features, differ to the previously describedliner segment 116.

A first difference is that, because this liner segment 116′ lines (andprotects) the end of the helical blade 106, the liner element 120′comprises a secondary mounting portion (in the form of a socket 132′) onan end surface 154 (i.e. a radially extending edge) of the liner element120′. The wear member 122′ that mounts to this socket 132′ differs tothose previously described in that it does not have a generally elongateform with a rectangular profile. The wear member 122′ includes a bodyportion 156 that is similarly shaped to the previously described wearmembers 122, and a wedge portion 158. The body portion 156 extends alongthe distal edge 126 of the liner element 120 and the wedge portion 158projects outwardly from the end surface 154 of the liner element 120′(when mounted thereto). In this way, the wear member 122′ wraps aroundthe edge surfaces 126, 154 of the liner element 120′ that wouldotherwise be exposed.

The upper 160 and lower 162 surfaces of the wedge portion 158 taperinwardly from an end 164 at which the wear member 122′ is mounted to theliner element 120, to a distal end 166. Although the thickness of thewear member 122′ is generally consistent, a raised padded region 168projects from an underside 162 of the wear member 122′. This paddedregion 168 corresponds to a lip 170 that projects from an underside 140of the liner element 120 and wraps around the end edge 172 (see FIG. 1B)of the helical blade 106. Thus, the lip 170 of the liner element 120protects the helical blade 106 and the padded region 168 protects theliner element 120′.

The socket 132′ of the liner segment 116 differs in that each of thesocket 132′ and protrusion 144′ comprises two recesses 148′, 150′, andtwo corresponding locks 152 for receipt in the lock passages defined bythose recesses 148′, 150′ when aligned. This may form a more secureconnection between the wear member 122′ and the liner element 120′ andmay further restrict rotation of the wear member 122′ relative to theliner element 120′ (i.e. by providing two fixing points).

In practice, each liner 114 may be installed by first forming aplurality of liner segments 116. Each liner segments 116 can be formedby mounting wear members 122 (via the sockets 132 and correspondingprotrusions 144) onto a liner element 120. Once assembled, the linersegments 116 can be mounted to the blades 106 to form liners 114.

An alternative installation method may involve first mounting linerelements 120 to the blades 106, and subsequently mounting wear members122 to the mounted liner elements 122 so as to form the liners 114.

Maintenance of the liners 114 may include replacing individual wearmembers 122 or replacing entire liner segments 116 (with the wearmembers 122 mounted thereto). Replacement of a wear member 122 (e.g. dueto particular wear of that wear member 122) may be performed by removingthe lock 150 of that wear member 122 from the aligned bores 148, 142(e.g. using a tool) and, subsequently, removing the protrusion 144 fromthe socket 132. A replacement wear member 122 can then be mounted to theliner element 120 at the location of the previously removed wear member122.

FIG. 2 provides an alternative arrangement for mounting one or more wearmembers 222 to a liner element 220. This arrangement includes a mountingmember in the form of a base plate 282. The base plate 282 mounts at asecondary mounting portion of the liner element 220, which is in theform of a bore 232, and further mounts at the wear member mountingportion of the wear member 222, which is also in the form of a bore 244.In this way, the wear member 222 is mounted indirectly to the linerelement 220.

The base plate 282 comprises first 284 and second apertures 286therethrough. When installed, the first aperture 284 aligns with thebore 232 of the liner element 220 such that the liner element 232 can besecured to the base plate 282 by receipt of a bolt 288 (e.g. hex-head)therethrough. The first aperture 284 also aligns with a blade aperture212 of the blade 206 such that the bolt 288 is also receivedtherethrough. In this way, the bolt 288 is received through the bore232, first aperture 284 and blade aperture 212 and can be retained inthat position by way of a nut and washer arrangement. When arranged inthis way, the base plate 282 is sandwiched between an upper surface ofthe blade 206 and a lower surface 240 of the liner element 220. A plug290 can also be received in the bore 284 of the liner element 220 tofill space that isn't taken up by the head of the bolt 288.

The second aperture 286 aligns with the bore 244 of the wear member 222.In this way the wear member 222 can be mounted to the base plate 282 byway of a further bolt 292 (which may have an oval shaped head). Thisbolt 292 can be received through the bore 244 and the second aperture286 and can be retained by way of a washer and nut arrangement.

Thus, the wear member 222 may be releasably mounted to the liner element220 via the base plate 282. This mounting allows the wear member 222 tobe replaced without needing to also remove the liner element 220 fromthe blade 206.

Now referring to FIGS. 3A to 4C, a further embodiment of a first linersegment, and a second liner segment are illustrated. The primarydifference between this embodiment and the previous embodiments is theform of the secondary mounting portion and the wear member mountingportion. The further embodiment of the first liner segment 316 andsecond liner segment 316′ generally includes the same features as thepreviously described liner segment 116 and 116′, respectively, butdiffers in that the secondary mounting portions and the wear membermounting portions are reversed. Like reference numerals are used forlike features. The prefix 3 is used in relation to the relevantreference numeral to identify the further embodiment.

FIGS. 3A to 3C generally shows a liner segment 316 (that comprises aliner element 120 and wear member 122) in more detail. The liner element120 includes a plurality (in this case three) secondary mountingportions. In the illustrated embodiment, the secondary mounting portionincludes protrusions 344 extending from the liner element 120. Locatingthe protrusions 344 on the first liner element 120 (rather than on thewear members 122) reduces the load on the protrusions 344 duringoperation of the agitator.

Each protrusion 344 extends from the distal edge 126 of the linerelement 120 and has a generally rectangular profile. Raised matingsurfaces 346 are provided on each protrusion 344 as previously describedin relation to the protrusion 144. A recess in the form of a bore 348extends through the protrusion 344 from the upper surface of theprotrusion 344 to the lower surface of the protrusion 344. The bore 348formed in the protrusion 344 has a generally circular cross-profile thattapers inwardly as described in protrusion 144, and is designed toreceive the locking pin described above. The edges of the protrusion 344and the distal edge 126 of the first liner element 120 are generallyrounded to provide smoother edge transitions.

The wear member 122 is mountable to the liner element 120 to protect theedge of the helical blade as discussed above. The wear member 122includes wear member mounting portions in the form of a plurality ofsockets 332 (in this case three to mate with the protrusions 344). Thesocket 332 formed in the internal surface 142 of the wear member 122 isa complementary shape to the protrusion 344. The sockets 332 beinglocated in the wear members 122 improves cleanability (from finematerial debris) prior to maintenance inspections.

The edges of the entrance and internal edges of the socket 332 arerounded, also complementary to the round edges of protrusion 344. Raisedmating surfaces 346 are provided in the socket 344 as previouslydescribed in relation to the socket 132. The socket 332 also includes anassociated recess, in the form of a bore 350, which extends from theupper surface 334 of the wear member 122 (at the internal surface)through to the lower surface 336 of the wear member 122 (i.e., so as toextend across the socket 332). The bore 350 extends at an angle (i.e. ondecline) relative to the upper surface 334 of the wear member 122 (i.e.in the direction of the internal surface 342 of the liner element 120).

As best illustrated in FIG. 3D, when the protrusion 344 is received inthe socket 332, the bore 350 of the socket 332 and the bore 348 of theprotrusion 344 align along a common longitudinal axis (to form a lockpassage) as described in previous embodiments. Lock 152 previouslydescribed in liner segment 116 can be received in the aligned bores 348,350, through the opening of the socket bore 350 at the upper surface 334of the wear member 122. Placement of protrusions 344 on the distal edge126 of the first liner element 120 means the locking pin can be locatedfurther from the machine center allowing for easier removal of thelocking pin from the bottom of wear member elements 122. In particular,as shown in FIG. 3D, when the liner segment 316 is mounted to theagitator blade 106, the aligned bores containing the locking pin 152 aredisposed beyond the outer edge 110 of the agitator blade 106. Thisprovides a clear lower opening to the bore 350 that allows the lock 152to be knocked out if need be. In this regard the bore 350 may tapertowards the lower opening to facilitate the locks removal through thelower opening.

FIGS. 4A, 4B and 4C illustrate the further liner segment 316′ with thefurther embodiment of the secondary mounting portion and the furtherembodiment of the wear member mounting portion. As discussed above, thefurther liner segment 316′ is configured for mounting at the in uselower end of the shaft 102 and as a result, the end wear member 122′includes the wedge portion to protect the leading edge of the helicalblade.

As shown in FIGS. 4A to 4C, the liner element 120′ further comprises aplurality (in this case four) secondary mounting portions, which in thisembodiment comprise protrusions 344 and 345. Advantageously, locatingprotrusions 344 and 345 on the first liner element 120′ reduces the loadon the protrusions 344, 345 during operation of the agitator.

The protrusion 345 that extends from the distal edge 126 has atrapezoidal profile complementary to the socket 333 located in the wearmember 122′. The protrusion 345 is larger than the protrusions 344 asprotrusion 345 is the leading edge and experiences more wear than otherthe wear members protrusions 344. Raised mating surfaces 346 areprovided on protrusion 345 as previously described on protrusion 344. Inthe illustrated embodiment, the protrusion 345 includes two recesses inthe form of two bores 348′ spaced apart that extends through theprotrusion 345 from the upper surface of the protrusion 345 to the lowersurface of the protrusion 345. The bores 348′ formed in the protrusion345 has a generally circular cross-profile that tapers inwardly aspreviously described in protrusion 344.

The locating protrusions 344 for the liner element 120′ are arranged tobe received in a socket (not shown) in the wear member 123′ which is ofthe same construction as the socket 332 of the wear member 122 shown inFIG. 3C. Again, providing the sockets on the wear members 122′, 123′improve cleanability (from fine material debris) prior to maintenanceinspections.

The end wear member 122′ includes the socket 333 formed in the endinternal surface 142′ has a trapezoidal profile and is larger in sizethan the previous embodiment of the socket 332. Raised mating surfaces347 are provided on internal surfaces as previously described on socket332. The socket 333 comprises two corresponding recesses in the form oftwo bores 350′ that are spaced apart and extend from the upper surface334′ of the wear member 122′ (at the internal surface) through to thelower surface 336′ of the wear member 122′ (i.e. so as to extend acrossthe socket 333). The bores 350′ formed in the wear member have agenerally circular cross-profile and extend at an angle as previouslydescribed in socket 332.

Referring to FIG. 4A, when the protrusion 344, 345 is received in thesocket 332, 333, the bores 350′ of the socket 332, 333 and bore 348′ ofthe protrusion 344, 345 align along a common longitudinal axis (to forma lock passage) as described in previous embodiments. The lock 152previously described in relation to the liner segment 116 can bereceived in the aligned bores 348′, 350′, through the opening of thesocket bore 350′ at the upper surface 334′ of the wear member 122′.

Variations and modifications may be made to the parts previouslydescribed without departing from the spirit or ambit of the disclosure.

For example the number of wear members per liner element can differ. Forexample, the liner element may only include one wear member, or twoliner elements may share a wear member. Similarly, each liner elementmay include more than three wear members.

The number of secondary mounting portions may differ per liner element,and the number of wear member mounting portions may differ per wearmember. The nature of the mounting portions may differ. It would beappreciated by the skilled person that other releasable mounting meansmay be used to mount the wear members to the liner element. For example,fasteners, depressible detents, snap-fit, and other such releasablemounting arrangements may be used.

The shape of the liner elements may differ to that described above. Forexample, liner elements in the form of a sector of a circle (or anentire circle) may be provided for agitators comprising disc shapedblades as opposed to the helical blades described above.

In an alternative embodiment (to that described above), the linersegment may be formed of a body portion and a peripheral portion that isformed of a different material to the body portion. The peripheralportion may be permanently secured or fixed to the body portion (incontrast to the releasable wear members). The material of the peripheralportion may be selected so as to be particularly suitable for resistingwear.

In the claims which follow and in the preceding description of theinvention, except where the context requires otherwise due to expresslanguage or necessary implication, the word “comprise” or variationssuch as “comprises” or “comprising” is used in an inclusive sense, i.e.to specify the presence of the stated features but not to preclude thepresence or addition of further features in various embodiments of theinvention.

1. (canceled)
 2. A wear member which forms part of a liner segmentconfigured for lining a vertical grinding mill agitator, the agitatorcomprising a shaft and at least one blade projecting from the shaft, aliner segment being configured to line the at least one blade of thevertical grinding mill agitator, the wear member comprising: a body, anda wear member mounting portion for releasably mounting the wear memberto a corresponding mounting portion of a liner element of the linersegment, wherein the wear member mounting portion comprises either aprotrusion for receipt in a socket of the corresponding liner elementmounting portion or a socket for receipt of a protrusion of thecorresponding liner element mounting portion, the protrusion or thesocket extending in a single direction configured to allow independentreplacement of the wear member.
 3. The wear member of claim 2, whereinthe liner segment comprises a plurality of wear members.
 4. The wearmember of claim 2, wherein the wear member is configured to mount to adistal edge of the liner element.
 5. The wear member of claim 4, whereinthe distal edge is distal from the shaft when the liner element ismounted to the at least one blade.
 6. The wear member of claim 4,wherein the distal edge comprises an enlarged portion that defines a lipextending along the distal edge, wherein the lip extends over an edge ofthe at least one blade when mounted thereto.
 7. The wear member of claim2, wherein the protrusion comprises at least one first recess, and thesocket comprises at least one corresponding second recess.
 8. The wearmember of claim 7, wherein the at least one corresponding second recessis transverse and intersects the socket.
 9. The wear member of claim 7,wherein the at least one first recess and the at least one correspondingsecond recess are arranged such that when the protrusion is received inthe respective socket, the at least one first recess of the protrusionand the at least one corresponding second recess of the respectivesocket align to define a locking passage arranged to receive a lock tosecure the wear member mounting portion to the corresponding liningelement mounting portion.
 10. The wear member of claim 9, furthercomprising a lock received in the lock passage to secure the protrusionin the respective socket.
 11. The wear member of claim 10, wherein thelock comprises a retainer for releasably retaining the lock in aposition in which the lock secures the protrusion in the respectivesocket.
 12. The wear member of claim 2, wherein the liner element isformed of a different material to the wear member.
 13. The wear memberof claim 2, wherein the at least one blade is a helical blade whichterminates at a lower end of the shaft.
 14. The wear member of claim 13,wherein the wear member comprises an end wear member configured formounting at the lower end of the shaft.
 15. The wear member of claim 14,wherein the end wear member comprises a wedge portion that includesupper and lower surfaces that taper from the body to a distal end of theend wear member.